1. Field of the Invention
This invention generally relates to photovoltaic cell and integrated circuit (IC) fabrication and, more particularly, to a method for forming a textured thin film from a printed seed layer pattern using a chemical bath deposition process.
2. Description of the Related Art
The patterning of conductive oxides is typically accomplished by photolithographic patterning and employing a dry or wet chemical etch process to remove unwanted areas of conductive oxides. Materials need to be patterned so that useful circuits can be defined. However, photolithographic patterning requires expensive equipment and the process must pattern active materials in an additive fashion.
In contrast to photolithographic patterning techniques, it is becoming common to pattern some thin film materials more simply using a printing deposition process. A conventional inkjet device, for example, includes a solution cartridge with a plurality of chambers. If the process is thermal, each chamber may include a heater. To eject a droplet from each chamber, a pulse of current is passed through the heating element causing a rapid vaporization of the solution in the chamber to form a bubble, which causes a large pressure increase, propelling a droplet of solution onto the substrate. The solution's surface tension and condensation, in cooperation with the contraction of the vapor bubble, pulls a further charge of solution into the chamber. The solution typically includes a volatile component to form the vapor bubble, otherwise droplet ejection cannot occur.
If the process is piezoelectric, each chamber may include a piezoelectric element. To eject a droplet from each chamber, an electrical signal is sent to the piezoelectric element causing a change in strain within the piezoelectric element. This strain creates an acoustic wave within the ink in the chamber. Upon interaction with the printhead nozzle, this acoustic wave generates a droplet that is propelled onto the substrate.
It would be advantageous if conductive oxide patterns could be formed on a substrate using a simple printing process.
It would be advantageous if the above-mentioned printing could form textured conductive oxide surfaces to enhance light absorption.